Apparatus and method for detecting a leak in a swimming pool

ABSTRACT

An apparatus and method for detecting water loss from a swimming pool includes a first container having an upper end, a lower end, an inner cavity and at least one opening allowing swimming pool water to flow in and out of said inner cavity; a substantially waterproof load cell positioned within the inner cavity of said first container, for measuring weight bearing thereon; and a second container having an upper end, a lower end, and an inner cavity closed to water flow, said second container positioned within the inner cavity of said first container having its lower end upon said load cell so as to bear weight thereon.

RELATED APPLICATION

[0001] This application claims priority from co-pending provisionalapplication Serial No. 60/251,367 which was filed on Dec. 5, 2000, andwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to the field of swimming pools andspas and, more particularly, to an apparatus and method for detectingleaks in pools and spas. The invention is equally applicable todetecting leaks in other containers for liquids.

BACKGROUND OF THE INVENTION

[0003] Swimming pools and spas have become quite popular and are commonnot only in public facilities but also in private homes. Occasionally, aswimming pool or spa appears to be losing water and the owner mustdetermine whether the loss is due to an undetected leak.

[0004] Pool and spa leaks in most cases are frustrating to diagnose. Itis also quite time consuming to test a pool or spa for a leak, forexample usually requiring two to three days of checking. Additionally,after a known leak has been repaired the pool or spa requires monitoringover a period of time to measure any incremental drop in pool level (dueto loss of water) in inches or fractions of inch. Such monitoring istypically accomplished over at least a twenty four hour period.

[0005] It is well known throughout the pool industry that leak detectionalmost always requires burdensome and redundant monitoring to establishtraceable leakage. Various types of interferences may hamper themonitoring effort, for example, rain, customer neglect, or traveldistances for monitoring personnel.

SUMMARY OF THE INVENTION

[0006] With the foregoing in mind, the present invention advantageouslyprovides an apparatus for detecting water loss from a swimming pool orspa. The apparatus comprises a first container, a substantiallywaterproof load cell, and a second container. The first container has anupper end, a lower end, an inner cavity and at least one openingallowing swimming pool water to flow in and out of the inner cavity. Thesubstantially waterproof load cell is positioned within the inner cavityof the first container for measuring weight bearing thereon. The secondcontainer has an upper end, a lower end, and an inner cavity closed towater flow, the second container being positioned within the innercavity of the first container having its lower end upon said load cellso as to bear weight thereon. This apparatus, of course, may be employedfor leak detection of a liquid contained in any other large container,not just in pools and spas.

[0007] A method aspect of the invention is useful for detecting loss ofa contained liquid from a container. The method comprises segregating afractional volume of the contained liquid so as to extend above asurface of a total volume of contained liquid; weighing the fractionalvolume; holding the fractional volume segregated during a predeterminedtime; and detecting a sufficient increase in weight of the segregatedfractional volume relative to the total volume during the predeterminedtime to thereby indicate loss of contained liquid due to a leak in thecontainer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Some of the features, advantages, and benefits of the presentinvention having been stated, others will become apparent as thedescription proceeds when taken in conjunction with the accompanyingdrawings in which:

[0009]FIG. 1 is a side elevation schematic view of a prototype apparatusaccording to an embodiment of the present invention, wherein theapparatus is manually filled; and

[0010]FIG. 2 is a cutaway perspective view of a preferred embodiment ofthe apparatus of FIG. 1 having a pump-aided fill.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0011] The present invention will now be described more fullyhereinafter with reference to the accompanying drawings, in whichpreferred embodiments of the invention are shown. This invention may,however, be embodied in many different forms and should not be construedas limited to the illustrated embodiments set forth herein. Rather,these illustrated embodiments are provided so that this disclosure willbe thorough and complete, and will fully convey the scope of theinvention to those skilled in the art.

[0012]FIGS. 1 and 2 illustrate an apparatus 10 for detecting water lossfrom a swimming pool according to the present invention. As best shownin FIG. 1, a preferred embodiment of the apparatus 10 comprises a firstcontainer 12, a second container 14 positioned within the firstcontainer, and a load cell 16 for weighing the second container 14. Thefirst container 12 has an upper end 18, a lower end 20, and an innercavity 22 having at least one opening 24 allowing swimming pool water toflow in and out of the inner cavity. This opening 24 is preferably nearthe lower end 20 of the container and includes a hose 26, as shown inFIG. 1. The load cell 16 is substantially waterproof and is positionedwithin the inner cavity 22 of the first container 12 for measuringweight bearing thereon. The second container 14 also has an upper end28, a lower end 30, and an inner cavity 32, but the inner cavity 22 isclosed to water flow. The second container 14 is positioned within theinner cavity 22 of the first container 12, and its lower end 30 bearsupon the load cell 16 so as to place weight thereon. The apparatus 10also preferably includes a power source (not shown) connected to theload cell 16 to thereby provide power. The skilled will appreciate thatthe submersible load cell 16 is substantially waterproof for use in apreferred embodiment of the invention. Additionally, a display 34 may beconnected to the load cell 16 for displaying weight measured so that anoperator may monitor the apparatus 10. The invention also comprises aprocessor (not shown) connected to the load cell 16 for processingweight measurement information.

[0013] As shown in FIG. 1, the upper end 18 of said first container 12preferably has an opening connecting with said inner cavity 22 andincludes a cover 38 thereon. The load cell 16 further comprises ballastsufficient for holding said load cell submerged underwater, asillustrated in FIG. 1. Of additional advantage is a load cell 16 furthercomprising an alarm responsive to said load cell and a recorderresponsive to said load cell.

[0014]FIG. 2 illustrates an embodiment of the present invention whichincorporates a number of features not shown in the model of FIG. 1. Theadditional features described below have been incorporated in order tomake the invention more easily workable in the field, and also so as tosimplify training personnel in the proper use of the invention.

[0015] As shown in FIG. 2, the apparatus 10 includes a first container12, the outer container, having a substantially closed upper end 18, alower end 20, an inner cavity 22 extending within said container fromthe upper end to the lower end, and an opening 24 at the lower endincluding a valve thereon for allowing swimming pool water to flow inand out of said inner cavity. A substantially waterproof load cell 16 ispositioned within the inner cavity 22 of said first container 12 at thelower end 20 and is connected to a power source (not shown), formeasuring weight bearing thereon. A second container 14, the innercontainer, has an upper end 28, a lower end 30, and an inner cavity 32,and is positioned within the inner cavity 22 of said first container 12having its lower end 30 upon said load cell 16 so as to bear weightthereon. A water pump and siphon tube combination 44 having an air bleedvalve 46 fluidly connects the inner cavity 22 of said first container 12with the inner cavity 32 of said second container 14 for filling saidsecond container with water. The air bleed valve 46 is also useful whenremoving the apparatus 10 from the water, so as to close the bleed valveto let water flow out of the apparatus by back-siphon through theopening 46 in the lower end of the first container 12. As shown, theapparatus 10 also includes a plurality of adjustable support members 48connected to said first container 12 so as to allow leveling of theapparatus. Also included is a leveling indicator 50 preferablypositioned at the upper end 18 of the first container 12 forascertaining that the apparatus 10 is properly leveled during operation.A handle 52 is provided connected to said first container 12 for aidingin handling the apparatus 10.

[0016] Those skilled in the art will recognize that while a preferredembodiment of the invention has been described by way of example inreference to a swimming pool or spa, the invention is adaptable todetecting a fluid loss in many other large containers for liquids.

[0017] Additionally, it should be understood that the apparatus 10 ofthe present invention may be employed as part of a plurality of likedevices to monitor many pools or other contained liquid bodies at thesame time from a remote monitoring station. For example, the apparatus10 may comprise a processor (not shown) connected to the load cell 16,and having sufficient storage capacity for storing weight measurementinformation generated by said load cell. Stored information ispreferably stored in a computer readable medium. Also, the apparatus 10may further include a wireless transmitter (not shown) connected to theload cell 16 for transmitting weight measurements and stored informationto a remote monitoring station. In this manner, many such devices may beset up in pools throughout a city or region and be monitored from acentral location. The wireless transmitter may be configured tocommunicate through a global computer network such as the internet fortransmission of data, thus increasing the geographic range which may bemonitored from a central monitoring station.

[0018] With reference to Table 1, a typical method of the presentinvention describes the typical process of initial set up, placement,and leak test using the apparatus 10 illustrated in FIG. 2. The initialset up involves making several connections, including connecting theequalizer hose to the first container 12, connecting power to the waterpump and to the load cell and display. The air bleed valve may be openedto allow air inside the apparatus 10 to be expelled when water entersthe device, although this is not necessary. The water intake valve isthen opened to allow the first container 12 to be filled. The apparatus10 is then placed into the pool, preferably on a pool step so that theapparatus is only partially submerged, as best shown in FIG. 2. Onceplaced into the pool, the first container 12 will fill with water topool level. The apparatus 10 should then be checked to ensure that it issubstantially leveled and not standing at an angle due to pool floorinclination. Leveling of the apparatus 10 is best verified by checking abubble level gauge provided on the upper end of the first container 12,as shown in FIG. 2. If necessary, the leveling members may be adjustedto properly level the apparatus 10. The air bleed valve is then closed,and the water pump is energized so as to fill the second container 14with water to a desired level, preferably just above the pool level, tothereby increase the weight of the water column volume segregated insidethe second container 14 relative to the pool level. The water intakevalve of the first container 12 is then closed, and the apparatus 10 isallowed to stabilize by waiting a few minutes. The load cell isenergized and tared, that is, adjusted so that the display reads zeroweight. It is then preferable to wait a few minutes to ensure that theapparatus 10 has stabilized, and that the load cell remains zeroed. Atthis time, the leak test is started by activating a timer and recordingweight measurements by the load cell. It should be understood that theweight measurements and the recording thereof may be made on acontinuous basis, or at predetermined time intervals. TABLE 1 TYPICALMETHOD OF THE INVENTION START INITIAL SET UP A) CONNECT EQUALIZER HOSEB) CONNECT WATER PUMP TO POWER C) CONNECT LOAD CELL TO POWER AND DISPLAYD) OPEN AIR BLEED VALVE E) OPEN FIRST CONTAINER WATER INTAKE VALVEPLACEMENT A) PLACE APPARATUS INTO POOL B) ALLOW FIRST CONTAINER TO FILLTO POOL LEVEL ADJUSTMENT A) ADJUST LEVELING MEMBERS AND B) VERIFYAPPARATUS LEVEL BY INDICATOR C) CLOSE THE AIR BLEED VALVE D) ENERGIZEWATER PUMP AND FILL SECOND CONTAINER TO ABOVE POOL LEVEL E) CLOSE FIRSTCONTAINER WATER INTAKE VALVE F) ALLOW TIME FOR APPARATUS TO STABILIZE G)ENERGIZE LOAD CELL AND “TARE” BY ADJUSTING TO DISPLAY ZERO WEIGHT H)ALLOW TIME TO ENSURE LOAD CELL IS STABLE I) READJUST TO ZERO IFNECESSARY LEAK TEST A) START TIMING THE LEAK TEST AND B) RECORD WEIGHTREADINGS OVER TIME C) NO WEIGHT INCREASE INDICATES NO LEAK: STOP D)WEIGHT INCREASE INDICATES LEAK: FIX LEAK AND REPEAT FROM START

[0019] It is possible that in a pool which has a severe leak the waterlevel is decreasing at such a pace that it may be difficult to initiallystabilize the reading of the load cell at zero when beginning a leaktest. In such a situation, optionally, once the first container 12 isfilled to pool level the equalizer hose may be closed or raised abovethe pool water level to stop outflow of water into the pool. Once theequalizer hose is opened or released into the water, the load cell willbegin to register an increase in weight for the second container 14,signaling a severe leak.

[0020] In the method of the invention, a leak test may be run for anydesired length of time. Experience indicates, however, that running aleak test for a few minutes is sufficient to detect all or nearly allleaks. In many cases, a leak test of only a few hours is entirelyadequate for detecting a leak. Once an operator has Ad accumulatedcertain experience with the apparatus 10, the time period for anadequate leak test will become apparent according to circumstances, aswell as whether a test reading may need to be repeated.

[0021] Another aspect of the method of the present invention isdetection of loss of a contained liquid from a container other than apool or spa. This method, illustrated in FIG. 3, comprises segregating afractional volume of the contained liquid so as to extend above asurface of a total volume of contained liquid; weighing the fractionalvolume; holding the fractional volume segregated during a predeterminedtime; and detecting a sufficient increase in weight of the segregatedfractional volume during the predetermined time to thereby indicate lossof contained liquid due to a leak in the container.

[0022] Additional aspects of a preferred method of the invention includeprocessing information generated during weighing; displaying the weightof the fractional volume; and displaying a change in weight of thefractional volume. Also, it should be understood that weighing in themethod comprises submerged weighing in the contained liquid, and thatsubmerged weighing preferably comprises weighing under liquidproofconditions. Detecting may also further comprise processing informationgenerated during weighing. For most efficient monitoring of the methodby an operator, the method may include recording responsive to weighing,recording responsive to detecting, and signaling an alarm responsive todetecting. Other aspects of the method include storing in a computerreadable medium information generated during weighing, and wirelesslytransmitting information generated during weighing to a remotemonitoring station.

[0023] The following is a typical example of a preferred embodiment ofthe invention in operation, the apparatus 10 comprising the followingdescribed component parts, with reference to FIG. 1.

[0024] A main holding tank or first container 12, for which a standard5-gallon plastic bucket with handle could be used. Typical dimensionsare about 18 inches tall, about 11 inches in upper end diameter, andabout 10 inches in lower end diameter.

[0025] An equalizer hose 26 for connection to an opening 24 near thelower end of the first container 12. This is typically a {fraction(1/4)} inch internal diameter, reinforced vacuum hose having a length ofabout between four to eight feet.

[0026] A submersible load cell 16 and appropriate mounting and ballast.Experimental work with load cells from various manufacturers revealedthat Tedea-Huntleigh 1 KG max., #1024 T, and Revere SHB series 5 KG max.load cells measuring tenths of a gram throughout their range are mostuseful in the present invention. Typical measurements for such loadcells are about 6 inches in length, about 1-2 inches in height, and upto about 1 inch in width. The load cell 16 is best disposed with about a10 foot long cord to connect to a remote electronic read out. The loadcell 16 may be mounted on a {fraction (1/2)} inch thick piece of PVC,having an 8.5×8.5 inch octagon cut as a base. The top plate mounted onthe load cell is about 4.5 inches square, and {fraction (1/8)}″ thickclear plastic. The PVC base has sufficient remaining surface area aroundthe load cell 16 to accommodate lead ballast weights for maintaining theload cell submerged. In addition, the ballast is needed to keep theplastic bucket (first container 12) solidly in place at least partiallysubmerged and to combat the inherent buoyancy of the bucket when restingon the bottom of the pool.

[0027] An electronic readout display 34 and battery unit (not shown) arewired to the load cell. This unit preferably has internal specificationsfor typical scale use in weighing. The unit uses zero reset (also knownas tare), and can be operated with or without an interval timer. Thecalibration on a preferred LED display operates from 0.0 to 1 KG, intenths of gram increments. A model which has been found to performadequately is the Tara systems TR 1 NK, 12 volt, adapted to connect inthe present apparatus.

[0028] A weighing cylinder, or second container 14, must be chosen of anappropriate height depending on the water level in the pool to betested. Typically, this second container 14 will have an open top, and asealed bottom so that water does not come in and out of the containersinner cavity. Second containers ranging in height to accommodate waterlevels from about 4 inches to about 17 inches have been used in thisinvention.

[0029] A wind protective cover 38 is typically made of open cellpolyurethane foam, and having a diameter sized snugly to cover entiretop of the first container 12 holding tank. The cover 38, however, maybe made of any one of many suitable materials and may have any desiredthickness.

[0030] Set up and operation of the apparatus 10 in a typical leak testis as described above for the method of the invention. Experimentalresults during operational testing indicate that surface fluctuations inthe water would adversely affect the small measurements required in thisprocess. The typical swimming pool experiences such fluctuations due towind and air currents, resulting in random and localized fluctuations inthe water level. A slight breeze produces dramatic changes in the watersurface, even though not seen by the naked eye. Therefore, baffling isadvantageous for suppression of such uncontrolled water levelfluctuations and is provided by the first container 12, which forms anouter barrier to these fluctuations. In a preferred embodiment thisbaffling is aided by the equalizer hose 26 connected to the opening nearthe lower end of the first container 12. The equalizer hose is mostadvantageously deployed when extending to the very bottom, or deepestpart of the pool. Optionally, in situations where extreme fluctuationsare encountered, the equalizer hose 26 may be provided with a dampenerto help prevent undue fluctuations in water level within the firstcontainer 12.

[0031] The load cell 16 is positioned on the bottom of the firstcontainer 12. The second container 14, or weighing cylinder, is thenfilled with water preferably to just above pool level, and is gentlylowered onto the load cell plate. In a preferred embodiment of thepresent invention, the second container 14 is filled until the LEDdisplay preferably reaches up to about 300 grams, and up to about 5minutes is allowed for the water level to stabilize inside the firstcontainer 12, or holding tank, via the equalizer hose 26. The beginningwater level in the swimming pool is then represented by the weightdisplayed for the second container 14 at this starting point. A windprotective cover 38, is then positioned to aid in preventing windgenerated surface turbulence.

[0032] In operation, if the pool experiences a drop in water level dueto volume loss, the water level inside the first container 12 will alsodrop by outflow through the equalizer hose 26. As the first container 12water level depletes along with the pool loss, the weight of the secondcontainer 14 on load cell 16 plate increases relative to the firstcontainer 12. Consequently, the load cell 16 detects the change inweight, and the display 34 will thus indicate even very small changes inthe water level.

[0033] The apparatus 10 may be left in the pool while the leakage istraced and repaired. Experience with the invention has shown that if thedisplay stops indicating a change in weight and is stable for at leastabout ten to fifteen minutes it is reasonable to assume that the leakhas been successfully repaired. Further monitoring is generally notnecessary from this point. However, if the display 34 continues to showa slow increase in weight, this is an indication that one or more leaksremain.

EXAMPLE

[0034] The following is offered as a further example of apparatus 10calibration and leak detection. A typical pool that is losing about oneinch of water level a day drops approximately 0.0007 inch per minute,there being 1,440 minutes in one day. In order to approximate such aloss, it was calculated that the first container 12 has a surface areaof about 615 sq.cm. This surface area is adjusted by subtracting thecalculated surface area of the second container 14, or 79.5 sq.cm., asthis fits within the first container 12. The total remaining surfacearea of the first container 12 is, thus, 536 sq.cm.

[0035] The apparatus 10 as shown in FIG. 2 was tested in a simulation.The apparatus 10 was set up outside a pool, the first container 12 beingfilled with water to simulate water in a pool or spa. The load cell 16and second container 14 were set up as described above, and the testsimulation was begun by using a syringe to extract 0.7 cc of water fromthe first container 12. Within about one minute thereafter the display34 indicated that the load cell 16 had detected a weight change of 0.1g.

[0036] Calculating based on the known dimensions of surface area in thefirst container 12, had the test actually been run in a typical pool,the load cell 16 would have detected a change of approximately 0.0005inch in water level.

[0037] The apparatus 10 was further tested in a pool holding about19,000 gallons of water. The tested unit was installed on block supportsinside the vinyl liner pool. Due to the pronounced angle of the bottomthe unit was leveled to balance a leaning offset. Wind was blowing ingusts of about between 5 to 15 MPH, thereby creating undesirable ripplesand fluctuations along the pool surface. The apparatus 10 was set upgenerally as described above, and the load cell 16 was tared to zeroafter the apparatus was set up. A leak was then simulated in the pool byremoving 1 gallon of water from the pool with a bucket. Within about oneminute, the display registered an increase in weight of 0.4 grams. Thegallon of water was then poured back into the pool, and the displayreturned to zero within about 2 minutes. In this experimental examplethe apparatus 10 of the present invention detected a drop in volume ofabout {fraction (1/19000,)} and under wind conditions tending togenerate adverse surface fluctuations.

[0038] In view of the above description and examples, those skilled inthe art will appreciate that the present invention will materiallyenhance the quality of the environment by providing an apparatus andmethod for easily detecting water leaks from swimming pools. Waterconsumption by recreational water use has become an increasingly acuteconcern in many parts of the country where water shortages areexperienced due to population growth. The invention will make a positiveimpact in reducing water loss from leaking pools, and will thereby aidin slowing down demand for potable water in such areas, and in extendingthe viability of the water reservoir, be it an aquifer, or a waterimpoundment.

[0039] Those skilled in the art will recognize that it would beadvantageous to have the load cell 16 be adjustably calibrated ifnecessary to account for natural evaporation of water from the swimmingpool. In practice, it has been found that evaporation does not affectthe performance the apparatus in detecting pool leaks. The reason orreasons for lack of effect by evaporation is not fully understood,however, at least two possible explanations may apply. First, it may bethat evaporation affects the water in both the apparatus and theswimming pool equally, thereby not creating any detectable differencebetween the two. Second, it is also possible that natural evaporation isundetectable because it proceeds at a rate slow enough not to bemeasured within the relatively short monitoring periods when the presentapparatus is used.

[0040] Accordingly, in the drawings and specification there have beendisclosed typical preferred embodiments of the invention, and althoughspecific terms are employed, the terms are used in a descriptive senseonly and not for purposes of limitation. The invention has beendescribed in considerable detail with specific reference to theseillustrated embodiments. It will be apparent, however, that variousmodifications and changes can be made within the spirit and scope of theinvention as described in the foregoing specification and as defined inthe appended claims.

That which is claimed:
 1. An apparatus for detecting water loss from aswimming pool, said apparatus comprising: a first container having anupper end, a lower end, an inner cavity and at least one openingallowing swimming pool water to flow in and out of said inner cavity; asubstantially waterproof load cell positioned within the inner cavity ofsaid first container, for measuring weight bearing thereon; and a secondcontainer having an upper end, a lower end, and an inner cavity closedto water flow, said second container positioned within the inner cavityof said first container having its lower end upon said load cell so asto bear weight thereon.
 2. The apparatus of claim 1, further comprisinga power source connected to said load cell.
 3. The apparatus of claim 1,further comprising a display connected to said load cell for displayingweight measured by said load cell.
 4. The apparatus of claim 1, furthercomprising a processor connected to said load cell for processing weightinformation generated by said load cell.
 5. The apparatus of claim 1,wherein the upper end of said first container has an opening connectingwith said inner cavity and includes a cover thereon.
 6. The apparatus ofclaim 1, further comprising sufficient ballast for holding the apparatusat least partially submerged in water.
 7. The apparatus of claim 1,wherein the opening in said first container is positioned near the lowerend.
 8. The apparatus of claim 1, wherein the opening further comprisesa hose extending therefrom.
 9. The apparatus of claim 1, furthercomprising an alarm responsive to said load cell.
 10. The apparatus ofclaim 1, further comprising a recorder responsive to said load cell. 11.The apparatus of claim 1, further comprising a processor connected tosaid load cell, said processor including sufficient storage capacity forstoring weight information generated by said load cell.
 12. Theapparatus of claim 1, further comprising a wireless transmitterconnected to said load cell for transmitting weight information to aremote monitoring station.
 13. An apparatus for detecting water lossfrom a swimming pool, said apparatus comprising: a first containerhaving a substantially closed upper end, a lower end, an inner cavityextending within said container from the upper end to the lower end, anda first opening at the lower end including a valve thereon for allowingswimming pool water to flow in and out of said inner cavity; asubstantially waterproof load cell positioned within the inner cavity ofsaid first container at the lower end and connected to a power source,for measuring weight bearing thereon; a second container having an upperend, a lower end, and an inner cavity, said second container positionedwithin the inner cavity of said first container having its lower endupon said load cell so as to bear weight thereon; and a water pump andsiphon tube combination having an air bleed valve and fluidly connectingthe inner cavity of said first container with the inner cavity of saidsecond container for filling said second container with water.
 14. Theapparatus of claim 13, further comprising a plurality of adjustablesupport members connected to said first container so as to allowleveling of the apparatus.
 15. The apparatus of claim 13, furthercomprising a leveling indicator for ascertaining that the apparatus isproperly leveled during operation.
 16. The apparatus of claim 13,further comprising a handle connected to said first container for aidingin handling the apparatus.
 17. The apparatus of claim 13, furthercomprising a display connected to said load cell for displaying weightmeasured by said load cell.
 18. The apparatus of claim 13, furthercomprising a processor connected to said load cell for processing weightinformation generated by said load cell.
 19. The apparatus of claim 13,further comprising sufficient ballast for holding the apparatus at leastpartially submerged in water.
 20. The apparatus of claim 13, furthercomprising a second opening at the lower end of said first container,said second opening connecting the inner cavity of the first containerto outside and comprising a hose extending therefrom.
 21. The apparatusof claim 13, further comprising an alarm responsive to said load cell.22. The apparatus of claim 13, further comprising a recorder responsiveto said load cell.
 23. The apparatus of claim 13, further comprising aprocessor connected to said load cell, said processor includingsufficient storage capacity for storing weight information generated bysaid load cell.
 24. The apparatus of claim 13, further comprising awireless transmitter connected to said load cell for transmitting weightinformation to a remote monitoring station.
 25. An apparatus fordetecting loss of liquid in a contained body of liquid, said apparatuscomprising: a first container having an upper end, a lower end, an innercavity and at least one opening allowing the liquid to flow in and outof said inner cavity; a load cell submersible in the liquid andpositioned within the inner cavity of said first container, formeasuring a weight bearing thereon; and a second container having anupper end, a lower end, and an inner cavity closed to liquid flow, saidsecond container positioned within the inner cavity of said firstcontainer having its lower end upon said load cell so as to bear weightthereon.
 26. The apparatus of claim 25, further comprising a powersource connected to said load cell.
 27. The apparatus of claim 25,wherein said submersible load cell is substantially liquidproof.
 28. Theapparatus of claim 25, further comprising a display connected to saidload cell for displaying weight measured by said load cell.
 29. Theapparatus of claim 25, further comprising a processor connected to saidload cell for processing weight information generated by said load cell.30. The apparatus of claim 25, wherein the upper end of said firstcontainer has an opening connecting with said inner cavity and includesa cover thereon.
 31. The apparatus of claim 25, further comprisingsufficient ballast for holding the apparatus at least partiallysubmerged in water.
 32. The apparatus of claim 25, wherein the openingin said first container is positioned near the lower end.
 33. Theapparatus of claim 25, wherein the opening further comprises a hoseextending therefrom.
 34. The apparatus of claim 25, further comprisingan alarm responsive to said load cell.
 35. The apparatus of claim 25,further comprising a recorder responsive to said load cell.
 36. Theapparatus of claim 25, further comprising a processor connected to saidload cell, said processor including sufficient storage capacity forstoring weight information generated by said load cell.
 37. Theapparatus of claim 25, further comprising a wireless transmitterconnected to said load cell for transmitting weight information to aremote monitoring station.
 38. A method for detecting loss of acontained liquid from a container, the method comprising: segregating afractional volume of the contained liquid so as to extend above asurface of a total volume of contained liquid; weighing the fractionalvolume; holding the fractional volume segregated during a predeterminedtime; and detecting a sufficient increase in weight of the segregatedfractional volume relative to the total volume during the predeterminedtime to thereby indicate loss of contained.
 39. The method of claim 38,wherein the contained liquid comprises water and the container comprisesa swimming pool or spa.
 40. The method of claim 38, wherein detectingfurther comprises processing information generated during weighing. 41.The method of claim 38, further comprising storing in a computerreadable medium information generated during weighing.
 42. The method ofclaim 38, further comprising wirelessly transmitting informationgenerated during weighing to a remote monitoring station.
 43. The methodof claim 38, further comprising displaying the weight of the fractionalvolume.
 44. The method of claim 38, further comprising displaying achange in weight of the fractional volume.
 45. The method of claim 38,wherein weighing further comprises submerged weighing in the containedliquid.
 46. The method of claim 38, further comprising recordingresponsive to weighing.
 47. The method of claim 38, further comprisingrecording responsive to detecting.
 48. The method of claim 38, furthercomprising signaling an alarm responsive to detecting.
 49. A method fordetecting a leak in a first container containing a total volume ofliquid, the method comprising: segregating a fractional volume of theliquid in a second container; positioning the second container at apredetermined depth above bottom within the first container so that thesegregated fractional volume of liquid extends above a surface of thetotal volume of liquid in the first container; weighing the secondcontainer over a predetermined period of time while maintaining thepredetermined depth constant; and detecting a sufficient increase in theweight of the second container to thereby indicate a loss of totalvolume of liquid due to a leak in the first container.